Suppress parallel:prepare output

MSP-9197
Fix constant resolution on travis-ci

MSP-9197
Fix Metasploit::Framework.env specs

MSP-9197

When I added support for use RAILS_ENV to be compatible with
parallel_tests, I forgot to capture and restore its value when checking
that the default value for Metasploit::Framework.env is 'development'
Replace mock with double

MSP-9197

Get rid of deprecation warnings for rspec to try to remove excess lines
from spec log for travis-ci.